The 28 year old defender, who is set to undergo a medical and finalise personal terms at the west London club, was left out of the Spurs squad for Saturday's defeat to Newcastle.
Villas-Boas said: "His human qualities are highly appreciated by us and the football club.
"His skills as a footballer are second to none so we appreciate them as well.
"If we end up with a scenario with five central defenders there is more competition and there might be less opportunities.
"That's why we are willing to consider different options and we have allowed the player to speak to QPR."